Canon 8300 with the standard Canon inks.
Was fun to do, but bottom line is that variations in scanning technique and other things probably add up to noise errors that are as big as minor variations in the media and ink set. I called my efforts "unscientific" because for instance I didn't do basic stuff like comparing back to back measurements done at the same time, and as you say averaging, and on and on. Real science is too much work!
So to be honest my only truly reliable conclusion from that lazy experiment is that for my equipment, it's easier to scan coated canvas!
And to a lesser extent, the 3d graph of the coated hull as presented by i1Profiler showed a more even wireframe patchwork for the coated hull, which I take as evidence of relatively clean data. And it's not too hard to see that prints from the coated profile is a little more peppy in the highlights...although I have seen cases where the wrong profile applied to a particular media is sometimes jazzier than the correct profile.
But OTOH, with a set or readings extended over time you might usefully be able to pick up long term systemic errors...if only in the puck! All of which reminds of my favorite long-term science experiment failure which was the "discovery" of a planet around Barnard's star, which after countless, painful, hunched over hours of precision measuring turned out to be a periodic error in the gear train of the telescope. And more recently the the faster-than-light Cern neutrinos that were tracked down to a badly inserted plug.
Thanks for that myth-busting link digitaldog! I definitely need to spend some time there. Appeals to my deep cynical streak. We so badly want to have Faith in the things we depend upon, and that faith is so often misplaced.
Those are graphs from iccview.de. Absolutely for free and at the very least are useful for ballparking the differences between fairly different media.